Direct drive windshield wiper assembly
View Patent ↗A windshield wiper assembly including at least one motor having an output shaft and a windshield wiper operatively connected to the output shaft. The motor includes a stator adapted to provide an electromagnetic flux and a rotor assembly supported for rotation about the stator. The rotor assembly includes a back iron and an annular magnet mounted to the back iron so as to be disposed in radially spaced relationship about the stator. The rotor assembly is operatively connected to the output shaft and responsive to electromagnetic flux generated by the stator so as to provide a rotational force to the output shaft to drive the windshield wiper in repeated wiping motion across the windshield.
1. A windshield wiper assembly comprising:
at least one motor having an output shaft and a windshield wiper operatively connected to said output shaft such that said windshield wiper may be driven in repeated wiping motion across the surface of the windshield;
said motor including a stator adapted to provide an electromagnetic flux and a rotor assembly supported for rotation about said stator, said rotor assembly including a back iron defining an inner circumference, a rotor cap operatively coupled to said back iron and an annular magnet mounted to said inner circumference of said back iron so as to be disposed in radially spaced annular relationship about said stator, said motor further including a planetary gear set including a sun gear operatively supported by said rotor cap for rotation with said rotor assembly, said rotor assembly operatively connected to said output shaft through said rotor cap and said sun gear and responsive to the electromagnetic flux generated by said stator so as to provide a rotational force to said output shaft to drive said windshield wiper in repeated wiping motion across the windshield.
2. A windshield wiper assembly as set forth in claim 1 wherein said planetary gear set is operatively connected in co-axial relationship to said output shaft of said motor to reduce the speed of the rotational output of said motor to said windshield wiper.
3. A windshield wiper assembly as set forth in claim 2 wherein said planetary gear set further includes a ring gear, a carrier, and a plurality of planet gears operatively supported by said carrier, said planet gear is disposed in meshing relationship with said sun gear and said ring gear and operable to reduce the speed of the rotational output of said output shaft of said motor.
4. A windshield wiper assembly as set forth in claim 3 wherein said rotor assembly is operatively connected in driving relationship to said planetary gear set.
5. A windshield wiper assembly as set forth in claim 4 wherein said rotor cap has a central opening, said central opening including a plurality of splines, said sun gear including a plurality of teeth that are adapted to receive in meshing relationship with said splines formed in said central openings of said rotor cap.
6. A windshield wiper assembly as set forth in claim 1 wherein said motor includes a latching mechanism for securing said rotor assembly and thus said output shaft of said motor in non-rotational disposition when said motor is off.
7. A windshield wiper assembly as set forth in claim 6 wherein said rotor assembly includes a plurality of notches, said latching mechanism including an electromagnetic actuator which is operable to engage at least one of said notches formed on said rotor assembly to immobilize said rotor assembly when said motor is off.
8. A windshield wiper assembly as set forth in claim 7 wherein said plurality of notches are defined on at least one end of said back iron.
9. A windshield wiper assembly as set forth in claim 1 wherein said annular magnet is a unitary molded permanent magnet.
10. A windshield wiper assembly as set forth in claim 9 wherein said molded permanent magnet is made of elements including niobium, iron, and boron.